Data Acquisition at the Front-End of the Mu3e Pixel Detector
Ann-Kathrin Perrevoort on behalf of the Mu3e Collaboration
Physikalisches Institut, Heidelberg
DPG Spring Meeting, Hamburg, February 29, 2016
Expectation from lepton mixing:
BRµ→eee ∼ (∆mm22ν
W )2 <10−54
Observation of µ →eee is a clear sign for New Physics
SUSY, extra heavy vector bosons (Z′), . . .
The Mu3e Experiment
Mu3e: Search forµ →eee down to BR<10−16 (90%CL)
• High muon stopping rates ∼ 2⋅109muons/s
• Background from SM decayµ → eeeννand accidental combinations
▸ Excellent momentum and vertex resolution
▸ Precise timing
• Momentum of decay electrons: ∼ 15 − 53 MeV/c
▸ Low material budget to reduce scattering
A. Perrevoort (PI HD) Pixel Detector Front-End at Mu3e DPG 2016 2 / 11
Thinned Si pixel sensors +Scintillating fibres and tiles
Target Inner pixel layers
Scintillating fibres
Outer pixel layers Recurl pixel layers
Scintillator tiles
μ Beam
Currently: In 2018:
DAQ Concept
Triggerless data acquisition Front-end board(this talk)
▸ Decode and merge data of∼15(36)sensors
▸ Time-sorting
Switching board(T22.5)
▸ Switch between front-end and filterfarm
▸ Merge data of sub-detectors GPU filterfarm(T42.5, T42.6)
▸ Fast track finding and online reconstruction
▸ Reduce data rate by a factor∼1000
1056 Pixel Sensors
up to 36 1.25 Gbit/s links
FPGA FPGA FPGA
...
Switching Boards
Data Collection
Server
Mass Storage Gbit Ethernet
Switching boards 34 FPGAs
1 6 Gbit/s link each
12 10 Gbit/s links per Switching Board 2 Inputs each
GPU PC
GPU PC
GPU 12 PCs PC
Front-end boards
Switching boards
Filterfarm
A. Perrevoort (PI HD) Pixel Detector Front-End at Mu3e DPG 2016 4 / 11
Sensor (T72.1 - 72.3)
• Integrated signal processing
▸ Amplification and signal shaping
▸ Hit detection
• Internal state machine
▸ Column-wise readout time structure is ‘lost’
▸ 8b/10b encoded data:
hit: time stamp, pixel address or counter
▸ LVDS link at up to 1.25 Gbit/s Up to 30 Mhits/s can be read out
P-substrate N-well
Particle E field
I. Peri´c, NIM A 582 (2007)
MuPix7 Prototype
• High Voltage Monolithic Active Pixel Sensor (T72.1 - 72.3)
• Integrated signal processing
▸ Amplification and signal shaping
▸ Hit detection
• Internal state machine
▸ Column-wise readout time structure is ‘lost’
▸ 8b/10b encoded data:
hit: time stamp, pixel address or counter
▸ LVDS link at up to 1.25 Gbit/s Up to 30 Mhits/s can be read out
Expected≤8 Mhits/s on busiest sensor at 108µ/s
Pixel Matrix
Periphery
A. Perrevoort (PI HD) Pixel Detector Front-End at Mu3e DPG 2016 5 / 11
Sensor (T72.1 - 72.3)
• Integrated signal processing
▸ Amplification and signal shaping
▸ Hit detection
• Internal state machine
▸ Column-wise readout time structure is ‘lost’
▸ 8b/10b encoded data:
hit: time stamp, pixel address or counter
▸ LVDS link at up to 1.25 Gbit/s Up to 30 Mhits/s can be read out
Pixel Matrix
Periphery
MuPix7 Prototype
• High Voltage Monolithic Active Pixel Sensor (T72.1 - 72.3)
• Integrated signal processing
▸ Amplification and signal shaping
▸ Hit detection
• Internal state machine
▸ Column-wise readout time structure is ‘lost’
▸ 8b/10b encoded data:
hit: time stamp, pixel address or counter
▸ LVDS link at up to 1.25 Gbit/s Up to 30 Mhits/s can be read out
Expected≤8 Mhits/s on busiest sensor at 108µ/s
Pixel Matrix
Periphery
A. Perrevoort (PI HD) Pixel Detector Front-End at Mu3e DPG 2016 5 / 11
Sensor (T72.1 - 72.3)
• Integrated signal processing
▸ Amplification and signal shaping
▸ Hit detection
• Internal state machine
▸ Column-wise readout time structure is ‘lost’
▸ 8b/10b encoded data:
hit: time stamp, pixel address or counter
▸ LVDS link at up to 1.25 Gbit/s Up to 30 Mhits/s can be read out
Pixel Matrix
Periphery
MuPix7 Prototype
• High Voltage Monolithic Active Pixel Sensor (T72.1 - 72.3)
• Integrated signal processing
▸ Amplification and signal shaping
▸ Hit detection
• Internal state machine
▸ Column-wise readout time structure is ‘lost’
▸ 8b/10b encoded data:
hit: time stamp, pixel address or counter
▸ LVDS link at up to 1.25 Gbit/s Up to 30 Mhits/s can be read out
Expected≤8 Mhits/s on busiest sensor at 108µ/s
Pixel Matrix
Periphery
A. Perrevoort (PI HD) Pixel Detector Front-End at Mu3e DPG 2016 5 / 11
Sensor (T72.1 - 72.3)
• Integrated signal processing
▸ Amplification and signal shaping
▸ Hit detection
• Internal state machine
▸ Column-wise readout time structure is ‘lost’
▸ 8b/10b encoded data:
hit: time stamp, pixel address or counter
▸ LVDS link at up to 1.25 Gbit/s Up to 30 Mhits/s can be read out
Pixel Matrix
Periphery
MuPix7 Prototype
• High Voltage Monolithic Active Pixel Sensor (T72.1 - 72.3)
• Integrated signal processing
▸ Amplification and signal shaping
▸ Hit detection
• Internal state machine
▸ Column-wise readout time structure is ‘lost’
▸ 8b/10b encoded data:
hit: time stamp, pixel address or counter
▸ LVDS link at up to 1.25 Gbit/s Up to 30 Mhits/s can be read out
Expected≤8 Mhits/s on busiest sensor at 108µ/s
Pixel Matrix
Periphery
A. Perrevoort (PI HD) Pixel Detector Front-End at Mu3e DPG 2016 5 / 11
Sensor (T72.1 - 72.3)
• Integrated signal processing
▸ Amplification and signal shaping
▸ Hit detection
• Internal state machine
▸ Column-wise readout time structure is ‘lost’
▸ 8b/10b encoded data:
hit: time stamp, pixel address or counter
▸ LVDS link at up to 1.25 Gbit/s Up to 30 Mhits/s can be read out
Front-End for the MuPix Telescope
MuPix telescope (T99.5)
• Tests of new prototypes and system integration
• 4 planes of MuPix7
• Readout via Altera Stratix IV development boards
• Test beam at DESY, PSI, SPS, MAMI in 2015
A. Perrevoort (PI HD) Pixel Detector Front-End at Mu3e DPG 2016 6 / 11
• Receive data via LVDS at 1.25 Gbit/s
• Align to word boundary using K-words
• 8b/10b decoding
“Unpacker”
• Disentangle hit and counter data
• Remove K-words Hit sorter
• Merge data from 4 sensors to one datastream
• Sort hit data by time stamp PCIe
MuPix MuPix MuPix MuPix
LVDS LVDS LVDS LVDS
Front-End for the MuPix Telescope
Sort hits by time stamp on FPGA
• Dual-port RAM (74 kbit)
• Continuously write and read
• Address: 8b time stamp + 4b counter
• Divide memory in 8 blocks
• Simultaneous read & write on the same block forbidden
• Possible difficulties
Read/write conflict: ∼µs ‘old’ hits Overflow: >15 hits per TS
A. Perrevoort (PI HD) Pixel Detector Front-End at Mu3e DPG 2016 8 / 11
Sort hits by time stamp on FPGA
• Dual-port RAM (74 kbit)
• Continuously write and read
• Address: 8b time stamp + 4b counter
• Divide memory in 8 blocks
• Simultaneous read & write on the same block forbidden
• Possible difficulties
Read/write conflict: ∼µs ‘old’ hits Overflow: >15 hits per TS
Front-End for the MuPix Telescope
Sort hits by time stamp on FPGA
• Dual-port RAM (74 kbit)
• Continuously write and read
• Address: 8b time stamp + 4b counter
• Divide memory in 8 blocks
• Simultaneous read & write on the same block forbidden
• Possible difficulties
Read/write conflict: ∼µs ‘old’ hits Overflow: >15 hits per TS
A. Perrevoort (PI HD) Pixel Detector Front-End at Mu3e DPG 2016 8 / 11
Sort hits by time stamp on FPGA
• Dual-port RAM (74 kbit)
• Continuously write and read
• Address: 8b time stamp + 4b counter
• Divide memory in 8 blocks
• Simultaneous read & write on the same block forbidden
• Possible difficulties
Read/write conflict: ∼µs ‘old’ hits Overflow: >15 hits per TS
Front-End for the MuPix Telescope
Sort hits by time stamp on FPGA
• Dual-port RAM (74 kbit)
• Continuously write and read
• Address: 8b time stamp + 4b counter
• Divide memory in 8 blocks
• Simultaneous read & write on the same block forbidden
• Possible difficulties
Read/write conflict: ∼µs ‘old’ hits Overflow: >15 hits per TS
A. Perrevoort (PI HD) Pixel Detector Front-End at Mu3e DPG 2016 8 / 11
Sort hits by time stamp on FPGA
• Dual-port RAM (74 kbit)
• Continuously write and read
• Address: 8b time stamp + 4b counter
• Divide memory in 8 blocks
• Simultaneous read & write on the same block forbidden
• Possible difficulties
Read/write conflict: ∼µs ‘old’ hits Overflow: >15 hits per TS
Front-End for the MuPix Telescope
• Successfully tested MuPix readout via fast serial link
• Hit sorting has proven suitability in lab and at test beam
• Data loss≲1‰ due to delta electrons
• No overflow observed
0 5 10 15 20 25 30
0 5 10 15 20 25 30 35
column
row
Hit Rate per Sensor [kHz]
0 50 100 150 200 250 300
Efficiency
0.9988 0.999 0.9992 0.9994 0.9996 0.9998 1
Efficiency of Hit Sorter MuPix Telescope
PSI Testbeam Oct'15
A. Perrevoort (PI HD) Pixel Detector Front-End at Mu3e DPG 2016 9 / 11
the Test Beam Facility at DESY Hamburg (Germany), a member of the Helmholtz Association (HGF).
We would like to thank PSI for providing high rate test beams under excellent conditions.
We owe our SPS test beam time to the SPS team and our LHCb colleagues, especially Heinrich, Kazu and Martin.
We thank the Institut f¨ur Kernphysik at the Johannes Gutenberg University Mainz for giving us the opportunity to take data at the
Summary
Mu3e Search for LFV decayµ →eee with a sensitivity of BR<10−16 (90%CL) MuPix7 Thinned active pixel sensor (HV-MAPS)
Fast serial data transmission
DAQ First implementation of front-end firmware successfully tested in MuPix telescope Continuous data sorting by time stamp on FPGA working
Outlook Adapt to next MuPix prototype Scale up to read out∼15 sensors
to PC
PCIe
MuPix MuPix MuPix MuPix
LVDS LVDS LVDS LVDS
Further talks on Mu3e/MuPix: Mu3e Experiment:
MuPix:
MuPix Telescope:
T22.5, T42.5-7, T43.3, T75.7, T98.1 & 5 T72.1-3
T99.5
A. Perrevoort (PI HD) Pixel Detector Front-End at Mu3e DPG 2016 11 / 11
MuPix7 Thinned active pixel sensor (HV-MAPS) Fast serial data transmission
DAQ First implementation of front-end firmware successfully tested in MuPix telescope Continuous data sorting by time stamp on FPGA working
Outlook Adapt to next MuPix prototype Scale up to read out∼15 sensors
to PC
PCIe
MuPix MuPix MuPix MuPix
LVDS LVDS LVDS LVDS
Further talks on Mu3e/MuPix:
Mu3e Experiment: T22.5, T42.5-7, T43.3, T75.7, T98.1 & 5